Blade for a gas turbine and casting technique method for producing same

Abstract

A blade for a gas turbine has a leading edge and a trailing edge, and an interior cavity, which is delimited by internal surfaces, for guiding cooling air therethrough. A multiplicity of turbulators or pins, which are formed on the wall, are arranged in a distributed manner in the region of the trailing edge and project from the internal surfaces into the cavity, to improve the transfer of heat between the wall of the blade and the cooling air. An improvement of the internal cooling is achieved by the turbulators or pins extending into the cavity in a direction which can be freely selected within an angular range.

1 . A blade ( 10 ) for a gas turbine, said blade ( 10 ) having a leading edge ( 11 ) and a trailing edge ( 12 ), and an interior cavity ( 16 ), which is delimited by internal surfaces ( 19 ,  20 ), for guiding cooling air therethrough, wherein for improving the transfer of heat between a wall ( 15 ) of the blade and the cooling air, a multiplicity of members ( 18 ), which are formed on the wall ( 15 ) to improve cooling, are arranged in a distributed manner in the region of the trailing edge ( 12 ) and project from the internal surfaces ( 19 ,  20 ) into the cavity ( 16 ), the members ( 18 ) extend into the cavity ( 16 ) in a direction which can be freely selected within an angular range. 
     
     
         2 . The blade as claimed in  claim 1 , wherein the members are turbulators or pins ( 18 ) which extend into the cavity ( 16 ) in a direction which is essentially perpendicular to the associated internal surface. 
     
     
         3 . A method for producing a blade ( 10 ) for a gas turbine by a casting technique, said blade ( 10 ) having a leading edge ( 11 ) and a trailing edge ( 12 ), and an interior cavity ( 16 ), which is delimited by internal surfaces ( 19 ,  20 ), for guiding cooling air therethrough, wherein for improving the transfer of heat between the wall ( 15 ) of the blade and the cooling air, a multiplicity of members ( 18 ), which are formed on the wall ( 15 ) to improve cooling, are arranged in a distributed manner in the region of the trailing edge ( 12 ) and project from the internal surfaces ( 19 ,  20 ) into the cavity ( 16 ), the members ( 18 ) extend into the cavity ( 16 ) in a direction which can be freely selected within an angular range, the method comprising the following steps:
 providing a core mold ( 23 ;  23   a, b ) for forming a casting core ( 21 ) which keeps the cavity ( 16 ) of the blade ( 10 ) free,   producing the casting core ( 21 ) is by means of the core mold ( 23 ;  23   a, b );   removing the casting core ( 21 ) from the core mold ( 23 ;  23   a, b ); and   casting the blade ( 10 ) by the casting core ( 21 ), wherein the core mold ( 23 ;  23   a, b ) which is provided in the first step comprises two mold halves ( 23   a, b ), which during demolding are drawn apart in a first direction, wherein at least one mold insert ( 27 ,  28 ), which is provided for forming the members ( 18 ), is arranged in the mold halves ( 23   a, b ) in the trailing edge region, and in the third step, after the parting of the mold halves ( 23   a, b ) in the first direction, the at least one mold insert ( 27 ,  28 ) is withdrawn from the formed casting core ( 21 ) in a second direction which differs from the first direction.   
     
     
         4 . The method as claimed in  claim 3 , wherein the second direction is perpendicular to the internal surface ( 19 ,  20 ) which is associated with the members ( 18 ). 
     
     
         5 . The method as claimed in  claim 3 , wherein a plurality of mold inserts ( 27 ,  28 ) are arranged in the mold halves ( 23   a, b ) and during demolding are withdrawn from the formed casting core ( 21 ) in different directions which differ from the first direction.